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arXiv 0907.0608astro-ph.SRastro-ph.IM
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在CoRoT目标HD 181906中的低振幅类太阳振荡

Solar-like oscillations with low amplitude in the CoRoT target HD 181906

R. A. Garcia, C. Regulo, R. Samadi, J. Ballot, C. Barban, O. Benomar, W. J. Chaplin, P. Gaulme, T. Appourchaux, S. Mathur, B. Mosser, T. Toutain, G. A. Verner, … 展开作者

R. A. Garcia, C. Regulo, R. Samadi, J. Ballot, C. Barban, O. Benomar, W. J. Chaplin, P. Gaulme, T. Appourchaux, S. Mathur, B. Mosser, T. Toutain, G. A. Verner, M. Auvergne, A. Baglin, F. Baudin, P. Boumier, H. Bruntt, C. Catala, S. Deheuvels, Y. Elsworth, S. J. Jimenez-Reyes, E. Michel, F. Perez Hernandez, I. W. Roxburgh, D. Salabert

摘要:

内容:F8恒星HD 181906(有效温度约6300 K)在第一次长距离运行期间被CoRoT卫星观测了156天。对数据的分析揭示了类似太阳的声波振荡的频谱。然而,目标的模糊性(mv =7.65)意味着声学模式中的信噪比(S/N)相当低,并且这种低S/N导致分析的复杂性。目的:提取恒星的全局变量以及光变曲线功率谱中观测到的p模的关键参数。研究方法:利用光变曲线的功率谱、小波变换和光斑拟合,得到了恒星的平均自转速率和倾角。然后,利用功率谱的自相关性和功率谱的功率谱来适当地确定大分离度。最后,通过最大化全局拟合的可能性来估计模式参数,其中同时拟合多个模式。结果如下:我们已经能够推断出恒星的平均表面旋转速率(~4微赫兹),表明存在表面差异旋转,p模式的大分离(~87微赫兹),因此也有对应于声学模式泛音的脊。

英文摘要:

Context: The F8 star HD 181906 (effective temperature ~6300K) was observed for 156 days by the CoRoT satellite during the first long run in the centre direction. Analysis of the data reveals a spectrum of solar-like acoustic oscillations. However, the faintness of the target (m_v=7.65) means the signal-to-noise (S/N) in the acoustic modes is quite low, and this low S/N leads to complications in the analysis. Aims: To extract global variables of the star as well as key parameters of the p modes observed in the power spectrum of the lightcurve. Methods: The power spectrum of the lightcurve, a wavelet transform and spot fitting have been used to obtain the average rotation rate of the star and its inclination angle. Then, the autocorrelation of the power spectrum and the power spectrum of the power spectrum were used to properly determine the large separation. Finally, estimations of the mode parameters have been done by maximizing the likelihood of a global fit, where several modes were fit simultaneously. Results: We have been able to infer the mean surface rotation rate of the star (~4 microHz) with indications of the presence of surface differential rotation, the large separation of the p modes (~87 microHz), and therefore also the ridges corresponding to overtones of the acoustic modes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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